To make an incredibly long story as short as possible, My best friend is 99% sure she's about to file for divorce. Her husband turned out to be a complete wanker.
He works away for weeks at a time and has been caught having an affair with some broad up in New Hampshire where he's staying.

The guy installs security systems for a living, cameras and such. To our knowledge hes barely computer literate though. Yet he somehow knows what shes doing online, the times, the sites, he can access her Gmail account and read her mails. He has even somehow bugged her cell phone and can see the numbers she calls and texts to.

I've been through the house quite thoroughly looking for any suspicious electronics, I work construction for a living so I'd like to think I have a pretty good idea where things of this sort could be hidden. So far nothing has turned up. Ive been through her computer multiple times, uninstalled any suspect programs, disabled all remote services, made sure the firewalls up and running etc. I've pretty much exhausted all my methods of "spy hunting", admittedly this is the first time I've ever done it lol.

She is trying to research everything related to the divorce, with my help of course but she can't do it privately from home because he seems to know what she's doing there at all times.

She's so paraniod that he's watching her somehow and based on the things he says related to her internet/comp usage it seems very likely he is. I was hoping you guys might be able to help me figure out what the hell he's up to.

Keylogger would gather this type of data. Just one of the many ways that such stuff can be gathered. however if he has access to her computer , then it is very easy to see what people have doing online.

He only has access to her computer when he's home, but that's the thing, he never is. The times he questions her about what she's doing he's up in NH staying in a hotel. We live in PA so he's hours away.

I'll try the 2 programs you mentioned, I scan it regularly with AVG and Spybot etc when I go over there.

Women like to think they are that important. Can't tell you how many women I've spoken to over the years that believe this when going through a divorce. Most of the time it's just contrived.

I doubt he's got the cell phone bugged. Maybe he's just logging into the website and seeing her calls. Maybe shes just that predictable with online activity. I'd say go to another PC and reset the online passwords she has.

It's likely that he installed some form of monitoring software on the computer.... These are not much different than what some companies use to monitor employees...

How can it be accessed remotely? Easily!

One software I know of off-hand actually collects information about what programs are being opened (and for how long), what web-sites the user is visiting, and monitors user input. Then you can have that information emailed or FTP'd somewhere. Very easy to setup and is not picked up by virus scanners with the proper settings. The one the company I worked for paid $20/PC for this software. Cant remember the name.

And no, you don't have to be a genius to get it going, its fairly easy.

If he has physical access to her computer and cell phone then there is nothing you can do really as far as preventing him from installing tracking/key loggers again if you do clean it.

I would set her with with a linux live cd/pen drive for her to browse and do what she does online. The router would be another way for him to track connections, so you would have to direct connect to the modem as well to hide everything.

I think I'm just gonna wipe the hd clean and reinstall windows for her. At least that would give me a clean slate and I can monitor what's installed from there on.

Other than using the Windows acct password is there anything else worth installing to prevent an unwanted user logging on to Windows ?

You could put Ubuntu on it until the whole thing blows over... I highly doubt her husband even remotely has a clue about that OS.

Also, there are things you can do to prevent unauthorized infiltration.. For starters, make sure the Administrator acccount has a password and change it once in a while. Also, set the account she uses to a plain user. That will prevent software from being installed on either account. Also, prevent elevation of user priveleges for windows update, that should close a few holes... Also, install a software firewall and use a strict per-application access policy.